Machine Tool
Single-pass bore finishing is not usually done in a milling machine for several reasons. Firstly, most milling machines have only one spindle, so changing the tool more than four to six times can increase cycle times significantly. Secondly, most workpieces that require this process are made on horizontal machining centers (HMC), which reduces float-ability due to gravity. Thirdly, the lubrication may not be sufficient, which can lead to material build-up between diamonds, diminishing the tool's effectiveness. Finally, if any chips remain from previous operations they can ruin the tool.
Instead, typically a dedicated machine tool is used. It has four to eight spindles and usually a rotary table. The cycle time for this type of setup is determined by the longest individual operation, which in this situation is determined by how long it takes to plunge and retract the tool through the bore. Throughput can be increased by completing two workpieces on each cycle; this is achieved by having two identical stations for each tool size so that two workpieces can be operated on concurrently.
Read more about this topic: Single-pass Bore Finishing, Process
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